Latchable electromagnetic contactor



April 3o, 1946.

D. ELLIS ET AL LATCHABLE ELECTROMAGNETIC CONTACTOR Filed Dec. 8, 1945 INVENTORS Jia/nes H. A/spac/z.

v ATTORNEY Patented Apr. 30, 1946 d I y l I 2,399,336

v LATCHABLE ELEo'raoMAGNE'rIc .,ooN'rAo'roR. I l' Delbert Ellis and James H. Alspach, Wilkinsburg,

Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh,

. Pennsylvania Pa., "a corporation ,of

f Application December s, 1943;'seria1No. 513.363 1 (o1/zones?) 11 Claims.

Our invention relates to electromagnetic contactors such as relays, overload switches, motor starters and the like devices.

It is an object of the invention to provide a contactor of this type that can be actuated manually and independently of the operating condition of the electromagnet, Vfor instance, in the eventof failure ofthe electromagnetic actuating means.V n

. Another object of our invention; is the provision of a -contactor that can be safely latched in its circuit opening or closing position, for instance,mwhen operating conditions are expected to involve4 high impact shocks or vibrations under which a magnetic contactorgmight perform uncontrolled and undesiredoperations, as may be the case on board warships.

A f-urtherobject of lour invention is to devise a contactor which is provided with latch means which are capable of latching the contactor in.

its on :or oil position during -periods of shocks or vibrations in order to thus prevent uncontrolled operation, while also permitting an actuation 4of the contacter,y subject to control by the attendant, duringfperiods of persistent shock or vibration so thatthe latch means can be released ;atwill within such periods.

Itisgalso an object, in conjunction with the foregoing, todevise a magnetically and manually actuable contactor, such as almotor starter, which requires extremely little space and a minimum of movable parts, especially for the manual control portion. More particularly, we aim at providing a -contactor of the type mentioned by ymerely adding a manual control and latch unit of small .compass to an otherwise Vcomplete and operative electromagnetic relay of customary design, thus obtaining a simple and inexpensive .dual actuation in accordance with any of the aforementioned objects.`

The invention is exempli-ed by the embodiment of an electromagnetic contactor, applicable as a motor starter, which is shown in the drawing 1by a part sec-tional side View in Fig. l, a part sectional front view in Fig. 2, the manual control portion being removed in the showing `of Fig. 1

.and separately illustrated by a front view in Fig.

3, a cross section in Fig. 4, and an illustration of -two appertaining latch levers in Figs. 5 and 6.

Referring to Figs. 1 and 2, a plate .I formingg :the mounting base of the individual contactar parts carries a magnet frame 2` with asolenoid lcoil 3. .A guiding structure 4 traverses the axial bore ,alcoli -3 and accommodatesa plunger type magnet core or armature 5 so as to permit the core va sliding vertical motion within the lcoil 3. A holding plate 6 is firmly` attached tothe core 5. An insulating body 1 is secured to the plate 6 by means of two brackets 8 and 9. Four movable contacts are mounted on the insulating body 1, each consisting of a saddle member such as the one'deno'ted by I0, a contact II slidably held *by the saddle member, and a contact spring I2 f straddled by a saddle. member and tending Vto move the contact II away from body 'I in order to establish'the desired contact pressurewhen the contact' engagement is closed. Four corresponding stationary contacts, such as the one denoted in Fig. l by I3, are mounted on an insulating body I4 rmly attached to the base plate I. In the illustrated position of the contacter, the movable contact and core assembly is in the lower position so that its contacts I I are separated from the respective stationary contacts I3. When the magnet coil '3 is energized, the core l5 is lifted so that the contact assembly is raised and an electric contact established between each pair of con tacts II and I3. 'This contact engage-ment exists as long as the magnet coil remainsenergized and is interrupted upon deenergization of the coil by the downward `motion of the movable assembly due toits gravity.

The magnet frame 2 forms two lugs 35 which according to Fig. 1 extend in a common planeet the front side of the contacter. A manual control and latching unit contained in aca-sing I5 is rmly secured to the lugs 35 by means of screws 36 as isv apparent fromFig. 2. The design of this unit will be understood from Fig. 2 in conjunction with Figs. 3 through 6 to which reference is had in the following.

The casing VI5 is traversed by a `pin I6 which extends 'in vparallel to the surface plane lof the base plate I and lies close tothe bottom portion of the casing I5. Two actuating levers I1 vand I8 are fulcrumed by pin I6. A contro1 lever IS also fulcrumed on pin I6 is located between levers .ITI and I8, the necessary spacing between the casing .and the lindividual levers being maintained by spacing washers 2U, 2|, 'and 22. 4The control lever I9 comprises a substantially U-shaped spring whose two arms 23 and 24 are resilient in the plane of illustration in Fig. 4 and have the tendency to spread apart so as to assume the position shown in this ligure. Two insulating nger portions 25 and 26 are mounted on the ends of arms 23 and 24, respectively.

The casing I5 has a raised or bulging portion provided with a slot 21 for the passage of varms '23' and 24 of the control lever I9. The lateral edges of :the slot 21 form three pairs of notches located at 28, 29 and midway between the locations 28 and 29 (Fig. 3). Due to the resiliency of the lever arms 23 and 24, these arms will catch into corresponding pairs of notches when the control lever is in the corresponding position.

The lever I'I according to Figs. 2, 4, and 5 has an angularly projecting nose 30 for engagement by the lever arm 23, and forms a latch or cam portion at 3| for cooperation with the movable contact assembly of the contactor. 'I'he lever I8 has an angularly projecting nose 32 for cooperation with the arm 24 of the control lever I9 and forms a cam or latch portion at 33 for coaction with the movable contact assembly.

When the control lever is in the mid-position, as shown in Figs. 2, 3, and 4, the lever I1 is disengaged from the contact assembly while the cam portion 33 of the lever I 8 lies underneath a shoulder 34 formed by the magnet core (Figs. 1 and 2),. In this mid-position, the manual control unit is inoperative and permits a free operation of the electromagnetic actuating device. That is, when the core 3 is energized and lifts the movable assembly, the shoulder 34 is free to move away from the lever portion 33.

In order to actuate or latch the contactor manually, the two handle portions 25 and 26 are pressed together by the attendant, thereby i'eleasing the arms 23 and 24 from the rests formed by the central pair of notches, so that the lever I9 can be moved into its upward or downward position. Moving the control lever downwardly toward its in position causes the arm 24 to abut against the nose 32 and to entrain the lever I8, thereby turning its cam portion 33 in the counterclockwise direction. If the contactor was in the circuit interrupting position shown in Figs. 1 and 2, the lever portion 33 abuts against the shoulder 34 and hence moves the contact assembly upwardly into contact closing position. When the control lever reaches its lowermost position, the arms 23 and 24 will spring into the rests formed by the pair of notches 29 so that the control lever is safely latched in the interrupting position of the contactor. If the contactor was in the circuit closing position before moving the control lever into the inf position, this motion has merely the effect of latching the contactor in the circuit closing position.

Starting again from the inoperative mid-position of .the control lever, the movement of this lever to the uppermost or out position determined by the pair of notches 28 will cause the lever arm 23 to entrain the nose 30 of leverv Il, thereby moving the latch portion 3I into the path of the movable contact assembly. Assuming that the contactor was in the illustrated circuit opening position, the lever portion 3| will reach a position close to the upper end of the bracket 9 (Fig. 2). Hence, upon latching of the control lever in the out position, the lever Il will prevent the movable contact assembly from being attracted by the magnet. If the magnet coil was energized before moving the control lever into the "out position, the lever portion 3l engages the bracket 9 in an earlier part of the lever motion and will then entrain the movable con tact assembly into the interrupting position against the force of the electromagnetic device.

It will be seen from the foregoing description that a contactor according to our invention permits a manual operation under control by the attendant and irrespective of the operating condition of the electromagnetic control device. Hence,

this contactor can be actuated in the case of failure of .the electromagnetic device or its current supply, or under conditions which render it desirable to operate the contactor at times or under conditions not intended for automatic actuation. It will also be understood from the foregoing that when the contactor is used under conditions where high impact, shocks, or vibrations are to be expected, the contacts may be locked at will either in the closing or opening position so that shocks cannot cause uncontrolled operations.

A contactor as described in the foregoing has also the advantage that the manually operable actuating and latch means are designed as a unit which can be attached to an otherwise complete and operative electromagnetic switch or relay. This permits using the same or a similar relay design with or without the manual control unit depending upon the particular purpose of the apparatus. The above described example shows further that the manual actuating and latching mechanism is of extremely simple design and Yfunction and requires very little space as compared with the dimensions of customary contactors.

While we have exemplified the invention by an embodiment showing a solenoid type magnetic device with a rectilinear motion of its movable assembly, it will be obvious to those skilled in the art that the invention can also be applied to contactors of other design and type, and that var.- ious modications and changes in design can be made without departing from the essential features of our invention. We, therefore, wish this specication to be understood as illustrative rather than in a limiting sense.

We claim as our invention:

l. An electric contactor having contact means movable between two contact Positions and biased toward one of them, electromagnetic actuating 'means for moving said Contact means into its other contact position, manual means arranged for moving said contact means between said contact positions independently of said electromagnetic means, said manual means having three operating positions and engaging said contact means in two of said three operating positions while being disengaged therefrom in said third operating position, and manually releasable means for locking said manual actuating means in any of said three operating positions.

2. An electric contactor having contact means movable between two contact positions and biased toward one of them, electromagnetic actuating means for moving said contact means into its other contact position, and movable latch means having three latching positions and being disengaged from said contact means when placed in one of said positions in order to then permit the operation of said electromagnetic means, said latch means lbeing arranged to engage said contact means when moved out of said one position to latch said contact means in said contact positions respectively.

3. An electric contactor having contact means movable between two contact positions and biased toward one of them, electromagnetic actuating means for moving said contact means into its other contact position, and operator-actuable latch means having three latching positions and 4being disposed for selectively latching said contact means in either of said contact positions thereby rendering said electromagnetic means ineffective when said latch means are placed in '(5 two of said latching positions respectively, said remaining latching position being provided for unlatching said contact means to render said electromagnetic means operative.

4. An electric Contact having contact means movable between two contact positions and lbiased toward one of them, electromagnetic actuating means for moving said contact -means into its other contact position, and operator-actuable latch means movable between two operative and one inoperative positions, said latch means engaging said contact means in said operative positions to hold it in its contact positions respectively While being disengaged in said inoperative position, and manually releasable means for locking said latch means in any of its three positions.

`5. An electric contactor having a contact controlling member movable between diierent contact positions, electromagnetic Vmeans for actuating said member, normally inoperative latch means for locking said member in said positions, a manual control movable between inoperative and operative positions for actuating said membe!` independently of said electromagnetic means, said control being disposed for engaging and actuating said latch means respectively when moved from said inoperative to an operative position, and manually releasable latch means forming part of said control for securing the latter in any of its selected positions.

6. An electric contactor having a contact controlling member movable between two contact positions, electromagnetic means for actuating said member, two independently movable actuating elements disposed for engaging and moving said member in opposite directions respectively and being normally out of engagement therewith, a movable manual control having two operative positions and an intermediate inoperative position for entraining said elements respectively when displaced from its inoperative position so as to move said member independently of said electromagnetic means, and spring biased latch means associated with said control for securing it in any of its three positions.

7. An electric contactor having a contact controlling member movable between two contact positions, electromagnetic means for actuating said member, two independently rotatable actuating levers disposed for engaging and moving said member in opposite directions respectively and being normally out of engagement therewith, a control lever having two operative positions and an intermediate inoperative position, said control lever being disposed for entraining said actuating levers respectively when displaced from its inoperative position so as to move said member independently of said electromagnetic means, and a stationary structure forming rests adjacent to the path of said control lever for securing it in any of its three positions.

8. An electric contactor having a contact controlling member movable between two contact positions, electromagnetic means for actuating said member, two independently rotatable actuating levers disposed for engaging and moving said member in opposite directions respectively and being normally out of engagement therewith, a control lever having two operative positions and an intermediate inoperative position, said control lever having a common fulcrum axis with said actuating levers and being disposed for entraining said actuating levers respectively when displaced from its inoperative position so as to move said member independently of said electromagnetic means, and a stationary structure forming rests adjacent to the path of said control lever, and said control lever being resilient so as to snap into said rests in any of its three positions.

9. An electric contactor having a contact controlling member movable between two contact positions, electromagnetic means for actuating said member, two independently rotatable actuating levers disposed for engaging and moving said member in opposite directions respectively and being normally out of engagement therewith, a control lever having two operative positions and an intermediate inoperative position, said control lever having two resilient arms for entraining said actuating levers respectively when displaced from its inoperative position so as to move said member independently of said electromagnetic means, and a stationary structure forming rests adjacent to the path of said control lever on both sides thereof for engagement by said two arms respectively in order to move said control lever in any of its three positions while releasing said control lever upon manual compression of said arms toward each other.

10. An electric contactor having contact `means movable between contact opening and contact closing positions and biased toward one o! said positions, electromagnetic actuating means for moving said contact means into said other position, latch means for locking said contact means selectively in either of said positions to prevent uncontrolled operation of said contact means, operator-controllable release means for unlocking said latch means, and operator-controlled means for actuating said contact means upon release of said latch means.

11. An electric contactor having contact means movable between contact opening and contact closing positions and biased toward one of said positions, electromagnetic actuating means for moving said contact means into its other contact position, latch means for locking said contact means in either of said positions to prevent uncontrolled operation of said contact means during periods of shock, operator-controllable release means for unlocking said latch means in order to permit controlled operation during such periods, and manual means forming part of said release means for actuating said contact means independent of the operation of said electromagnetic means.

DELBERT ELLIS. JAMES H. ALSPACH. 

